about jenkins.debian.net - or what Holger / Debian is doing with all these resources

(Automating all the tests!)

Holger Levsen <holger@debian.org>

Profitbricks Office, 2016-11-30, Berlin, Germany

about me

  • Debian user since 1995, contributing since 2001
  • Debian-Edu (Debian for Education), since 2003
  • DebConf organizer, founded the DebConf video team in 2005
  • Debian developer since 2007, holger@debian.og
  • Freelancer since 2004, holgerlevsen.de
  • Freelancer at Profitbricks from 2011-2013 and 2015

more about Debian QA and me

  • https://piuparts.debian.org since 2009 - today juggling with 648988 logs from 53158 packages in 28 suites with Andreas Beckmann
  • https://jenkins.debian.net since 2012
  • https://reproducible.debian.net since 2014
  • since 2015 funded by the Linux Foundation for working on https://reproducible-builds.org

other Debian QA efforts elsewhere

  • lintian.debian.org
  • ci.debian.net
  • periodic full archive rebuilds (amd64 only)

about jenkins.debian.net

  • resources sponsored by Profitbricks since 2012
  • first request on August 2nd 2012: 2-4 cores, 2GB RAM, 1 TB storage

Profitbricks resources used by jenkins.debian.net

  • 17 machines (16*Debian, 1*FreeBSD, 13*64bit, 4*32bit)
    in 2 datacenters (FKB + FRA)
  • 168 cores (148 AMD, 20 Intel) with 498/503 GB RAM
  • 2.9/3.1 TB HDD and 1.9/2 TB SDD storage
  • no static IP addresses, no idea about traffic (500gb/month?)
  • 2 DCD users: Mattia Rizzolo and me

jenkins.debian.net contributors:

  • Mattia Rizzolo, Valerie Young and others: reproducible Debian
  • Helmut Grohne: rebootstrap
  • Samuel Thibault: hurd + accessibility
  • Steven Chamberlain: kfreebsd
  • Phil Hands: lvc
  • Tomasz Nitecki: jenkins java support
  • 36 contributors to jenkins.debian.net.git in total

A quick detour about Debian release names

  • wheezy (Debian 7) = oldstable
  • jessie (8) = stable
  • stretch (9 = testing
  • sid = unstable
  • experimental

Benefits for debian

  • IRC / mail notifications, #debian-qa IRC channel and 11 other channels, more mailinglists
  • Early notifications of problems - though bugs still need to be filed manually
  • Countless bug reports, ie 2670 done ftbfs via reproducible… (and 500 open…)
  • jenkins.debian.net will become an offical service, jenkins.debian.org

chroot-installation tests

  • 338 jobs basically running apt install $metapackages
    (gnome, kde, cinnamon, lxde, xfce, qt4, qt5, haskell, developer, debconf-video, debian-edu)
  • new installations and upgrades tested in
    wheezy (98), jessie (147), stretch (153), sid (98)
  • wheezy monthly, jessie weekly, stretch every other day, sid daily

g-i-installation tests

  • tests Debian Installer (d-i) in graphical mode ("g-i") and text mode
  • creates videos and screenshots
  • plain Debian (installations and rescue mode) and Debian Edu
  • jessie, stretch and sid
  • linux, kfreebsd and hurd
  • finally almost deprecated today, will be replaced by lvc tests (libvirt-cucumber) maintained by Phil Hands

more debian-installer related jobs:

  • 97 packages (building udebs) triggered by commits to their git master branches
  • manual in 24 languages, also git triggered
  • lvc and d-i from proposed branches planned

37 debian-edu jobs:

  • 28 g-i tests for jessie and stretch
  • 8 debian-edu packages build triggerd by commits on their git master branches
  • very useful for debian-edu-doc which is published for 7 languages in HTML, PDF & EPUB format.


  • Cross bootstrap Debian from scratch…
  • alpha arm64 arm64ilp32 armel armhf hppa hurd-amd64 hurd-i386 i386 kfreebsd-amd64 kfreebsd-armhf kfreebsd-i386 m68k mips mips64el mips64r6el mipsel mipsr6el musl-linux-arm64 musl-linux-armhf musl-linux-i386 musl-linux-mips musl-linux-mipsel nios2 powerpc powerpcel powerpcspe ppc64 ppc64el s390x sh4 sparc sparc64 tilegx x32
  • Helmut Grohne files lots of cross-building and bootstrapping bugs.

more debian-qa related jobs:

  • orphaned packages without bug
  • dpkg trigger cycles
  • lintian, debhelper and piuparts are build on git commits in jessie, stretch and unstable
  • reproducible-builds.org - "btw": over 2600 'FTBFS' bugs found and fixed so far, ~400 open…
  • reproducible.debian.net / tests.reproducible-builds.org/debian/

    • created by 379 / ~350 jobs on jenkins.debian.net
    • it's not only about Debian anymore…

    The problem: Can we trust the build process?

    • One can inspect the source code of free software for flaws
    • But distributions provide binary/compiled packages

    The problem: nobody can trust any binary built anywhere anymore

    • To get users, go after the developers
    • Financial incentives to crack developer machines / build infrastructure
    • CVE-2002-0083: Remote root exploit in OpenSSH (single bit difference in binary)
    • Kernel module modifying source code when "viewed" by GCC only (see media.ccc.de)
    • Compromised Apple iOS SDK, Xcodeghost, etc.

    Our solution

      (we are still at step 1 here)
    • Ensure compilation of the same source always has bit by bit identical results
    • Multiple parties compare compilation results
    • Attacker needs to infect everybody simultaneously (or they are detected)

    We call this Reproducible Builds.

    • We think this should become the norm for free software.

    The motivation behind "reproducible" builds is to allow verification that no flaws have been introduced during the compilation process.

    Reproducible builds in Debian

    Continuously build every package twice, varying:

      • Time & date
      • Hostname & domain name
      • Filesystem (disorderfs)
      • Timezone & locale
      • uid & gid
      • GECOS information, the shell & a bunch of environment variables
      • Kernel & CPU type
      • and more…




      • Timestamps
      • Timezones & locales
      • Non-deterministic file ordering
      • Dictionary/hash key ordering
      • Users, groups, umask, environment variables
      • Build paths
      • Specifying the environment

    Other technical benefits

      • Faster to build; saves time, money & the environment
      • Easier to test changes/revisions
      • Unsafe behaviour (eg. internet access)
      • Unreliable / non-deterministic behaviours (eg. timing)
      • Finds bugs in uncommon timezones or locales
      • Detect corrupted build environments
      • Find future build failures (eg. expired certificates)

    Future work

    • .buildinfo files distribution unsolved (step 2)
    • How to make it meaningful for end-users (step 3)
    • Source code still vulnerable

    Beyond Debian…

    Reproducible Builds summits (Athens 2015, Berlin 2016)

    Projects using Profitbricks resources via jenkins.debian.net



    work in progress:

    Resources used for reproducibility testing on jenkins.debian.net, by architecture & sponsor

    • 13 amd64 systems, sponsored by Profitbricks
    • 4 i386 systems, sponsored by Profitbricks
    • 22 armhf systems, sponsored by vagrant@d.o, Debian & other donations
    • soon: 8 arm64 systems, sponsored by codethink.co.uk

    Usually I thank:

    Todays special thanks:

    • from Debian, jenkins.debian.net would not have been possible like this without your support!
    • from many many folks interested in Reproducible Builds!


    holger@debian.org B8BF 5413 7B09 D35C F026
    FE9D 091A B856 069A AA1C


    …and many thanks to Chris Lamb for the nice slide design!